Configure an Ultrasonic Sensor (Micro-RDK)

Configure an ultrasonic sensor to integrate the HC-S204 ultrasonic distance sensor into your machine:

Navigate to the CONFIGURE tab of your machine’s page in the Viam app. Click the + icon next to your machine part in the left-hand menu and select Component. Select the sensor type, then select the ultrasonic model. Enter a name or use the suggested name for your sensor and click Create.

Creation of a ultrasonic sensor in the Viam app config builder.

Edit and fill in the attributes as applicable to your sensor, according to the table below. Although "board" is marked as required in the RDK, it is not required for Micro-RDK usage.

{
  "trigger_pin": "<pin-number>",
  "echo_interrupt_pin": "<pin-number>"
}
{
  "trigger_pin": "15",
  "echo_interrupt_pin": "18"
}
{
  "components": [
    {
      "name": "<your-ultrasonic-sensor-name>",
      "model": "ultrasonic",
      "type": "sensor",
      "namespace": "rdk",
      "attributes": {
        "trigger_pin": "<pin-number>",
        "echo_interrupt_pin": "<pin-number>"
      },
      "depends_on": []
    }
  ]
}
{
  "components": [
    {
      "name": "my-ultrasonic-sensor",
      "model": "ultrasonic",
      "type": "sensor",
      "namespace": "rdk",
      "attributes": {
        "trigger_pin": "15",
        "echo_interrupt_pin": "18"
      },
      "depends_on": []
    }
  ]
}

The following attributes are available for ultrasonic sensors:

AttributeTypeRequired?Description
trigger_pinstringRequiredThe GPIO number of the board’s GPIO pin that you have wired to the trigger pin of your ultrasonic sensor.
echo_interrupt_pinstringRequiredThe GPIO number of the board’s GPIO pin that you have wired to the echo pin of your ultrasonic sensor. Please note that unlike the RDK ultrasonic sensor, you must not use a named pin associated with a digital interrupt configured on your board: it will not (currently) work.
timeout_msintOptionalTime to wait in milliseconds before initiating a timeout when requesting readings from your ultrasonic sensor.
Default: 50
Max: 100

Test the sensor

After you configure your sensor, navigate to the CONTROL tab and select the Sensors dropdown panel. If you have multiple sensors configured, your sensor will be listed here among others. To access detailed readings from your sensor, click on the Get Readings button.

The sensor component in the control tab

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